Inductors are used in many integrated circuit applications, such as for power regulation, filtering, and low ripple or fast transient responses during a load transient. For example, inductors are required in miniaturized devices that may include a voltage regulator (VR) in an integrated circuit, or a component in a low power application.
Unfortunately, an inductor in a voltage regulator power stage has two conflicting requirements: a lower ripple voltage with a slower transient response, or a higher ripple voltage with a faster transient response. Typically, an inductor with a high inductance value has a lower ripple, as such a lower core loss, but it suffers from a slower transient response. On the other hand, an inductor with a lower inductance value has a higher ripple, but it benefits from a faster transient response. As such, the inductor in the integrated circuit application is selected based on one of these two requirements.
In some applications, an inductor may need to be reconfigurable. To be reconfigurable, the inductance of the inductor should be capable of being selectively modified to more than one inductance value in a real time setting. Therefore, if the inductor can be reconfigured (or reset) in a real time setting, the inductor may satisfy both requirements and provide a low ripple voltage and a fast transient response. In other applications, the inductor may be required to reduce an undesirable voltage deviation (alternatively referred to as an overshoot or undershoot) during a load transient, which would essentially save passive costs in silicon and provide a smaller design platform. However, these requirements for a reconfigurable inductor have not been currently or adequately met.